BLUE-BREASTED WARBLER. 
67 
nightingale, and other delicate warblers; also ants’ eggs, 
meal, and earth-worms. Its quarrelsome disposition is shown 
when caged with another of its own species, in their continual 
battles, which, if not interrupted, would certainly end in 
the defeat and death of one of the combatants. 
It is probable that this, and many other species of our 
warblers, in pursuing their vernal and autumnal migrations, 
follow the course of large rivers, on account of the number¬ 
less insects, both aquatic and terrestrial, that are to be found 
upon their shores, and along the banks of the tributary streams 
that join their course. Those, especially, that travel early, such 
as the Blue-breasted Warbler, and the redbreast, must find 
such a route highly favourable to the satisfying the first demand 
of nature, that of food. Accordingly, we find Provence, 
Lorraine, and Alsace, mentioned as visited in great numbers 
by’the Blue-breasted Warbler and the redstart, and other 
summer birds, in the course of their migratory passage. This 
tract of country having, through its centre, the Rhone, the 
Rhine, and the Moselle, and being bounded on the eastern 
side by the mountains of Switzerland, and on the west by 
those of Languedoc, Burgundy, and Lorraine, leads from 
the Mediterranean directly into the heart of Europe, where 
these birds are seen in greater numbers, especially during 
their seasons of migration, than in any other part of Europe, 
and from whence they may speedily attain the northern 
countries they are known to frequent. 
The entire length of the Blue-breasted Warbler is five 
inches and a half: the beak measures four and a half lines 
from the forehead to the tip, and seven lines from the tip 
to the gape. The wing measures nearly three inches from 
the carpus to the tip ; and the tail extends, beyond the 
closed wings, one inch. The tarsus is an inch in length, and 
the middle toe seven lines and a half. 
The male, in adult plumage, has the whole upper parts, 
